350 Proceedings of the Royal Society 
I think not ; both because of the necessary roughness of their 
measuring without having made preparations 2 and 3 (of p. 340); 
and because their quantity for the north side differs by more than 
twice that difference from any other person’s measures of the same 
side. But then again, who will vouch for these other measurers? 
Some persons maintain that civil-engineers of the present day are 
so superior to those of the past, that Mr Inglis’ measures must be 
the best in the field ; others again rather hold the opposite. How 
then ought the mean of all the just-mentioned numbers be taken ? 
“ Shall I take the mean of all four of Mr Inglis’ sides as one side, 
“ and so give him a weight of one only, against each of the three 
“ older observers? Or shall I take each of his sides as a determi- 
“ nation as good as each of theirs, and in that case give him a 
“ weight of four, to their one each?” That, however, would not 
be paying sufficient respect to the exceeding care with which 
M. Jomard, and the Academicians accompanying him, say 
that they measured the north side ; while again, to give Messrs 
Aiton and Inglis the weight of one only, would not sufficiently 
mark a sense of approval of their having been the first known men 
to measure all four sides of the G-reat Pyramid’s base, from socket 
to socket ; and I was bound in honour, and as a witness, to testify 
for them there. So I settled to give them the weight of two. 
I do not pretend to say that I was quite right in that estimation 
of the probable worth of their measures. But I do mean to say, 
that having first of all printed those measures pure, simple, and 
complete — and then stated the principle on which I should take 
the mean — I took that mean honestly and fairly ; and its final 
result, to the nearest whole inch, came out truly 9142 inches. 
But the Proceedings' author implies that I did not take that 
mean honestly and fairly ; and there is the difference between us. 
His words are, “ he (Professor Smyth) takes two of them (Mr Inglis’ 
“ measures) 9114 and 9102 — ( but strangely not the largest , 9120) — as 
“ data; and strikes a new number out of these two, and out of the 
“ three previous measures of Jomard, Vyse, and Mahmoud Bey.” 
Now, if I had wilfully left out the largest number of the Inglis 
series, where each member had been considered of equal weight, — 
I should have been dishonest, and unworthy of fulfilling any 
scientific appointment. But I did not do so, either wilfully or 
